COLD STORAGE FACILITIES
By Cid Caba

DESIGNING ROOFS FOR COLD STORAGE FACILITIES

Cold Storage Facilities are Unique
When developing roofing design criteria for cold storage facilities, designers must be aware of the unique nature of these facilities.  Roofing over cold storage facilities is unlike standard roofing construction. Attention to detail, correct design, quality material, compatible material, and close supervision is required.

Prior experience in cold storage roofing and clear understanding of the critical nature of the cold storage-to-roof vapor barrier tie in by the roofing superintendent and installation crews is central to a successful installation.  Just as water should not be allowed to penetrate a standard roofing tie-in, vapor must not be allowed to permeate the vapor barrier tie-in.

When reroofing a cold storage facility, especially one currently in operation, more than the standard roof replacement criteria must be considered.

What can go wrong?
Unfortunately, the responsibility for ensuring a proper, uninterrupted vapor barrier seal lies with two different contractors.  The roofing contractor is responsible for maintaining a continuous seal at the roof level.  The cold storage contractor must properly construct the vapor barrier below the roofing level.  Many contractors and consultants have learned hard lessons about the consequences of faulty coordination between the various involved parties, interrupted seals, and improper construction of the vapor barrier.

Vapor leaks cause moist air leakage into the facility resulting in frost and ice formation, energy loss, and eventually expensive repairs.  In some cases, actual snow flake formations occur inside freezers.  Mechanical equipment supplying the facility can incur accelerated aging due to the difficulty in maintaining the required temperatures.

Shoddy workmanship is most often the source of cold storage facility vapor leaks.  Improper design also contributes to a range of problems.  Finally, damage to the barrier may result from excessive structural movement such as seismic activity or building settlement.

If major vapor leak problems occur, disrupting the successful performance of the cold storage facility and resulting in some of the conditions noted above, the following entities may get involved:

• Food and Drug Administration (FDA)
• Occupational Safety and Health Administration (OSHA)
• U.S. Department of Agriculture (USDA)

The results can be extremely costly to the facility operator, both in damage to the building and in loss of building contents or operations.

When vapor leaks occur after construction it is difficult to determine who or what is responsible.  Often destructive testing is required to determine the cause of the problem, the responsible party, and the proper corrective action.  The entire facility may be severely impacted.

How can I ensure success in the roof design on my cold storage facility?
IRC recommends a design team approach be used during the design development of a cold storage facility, incorporating qualified design professionals for each design discipline, including roofing.

If you are considering reroofing a cold storage facility, it is critical that a qualified roofing consultant be used.  Do not let the consultant learn about cold storage on your facility.  Ask for references from cold storage facilities listing size and location.  Using an unqualified consultant for this type of roofing construction can be a costly mistake for owners and designers.

IRC has assisted in successful major cold storage roofing design and construction projects throughout the United States for over 25 years assisting architects in design and peer review, as well as monitoring quality control during the roofing and vapor barrier construction.